With the accession of Charles, Maximilian's grandson becoming the Holy Roman Emperor, Frundsberg was made commander of the Imperial Army. Frundsberg remained very active in the development and execution of Landsknecht military strategy.

He was a brave and able soldier who served the Habsburgs for almost three decades. Although a mercenary, he was unfailingly loyal to his emperor. Exhausted and ill from combat, von Frundsberg died in Mindelheim in August 1528.